1. Field of the Invention
The present invention relates generally to a thin film transistor (TFT) array panel for liquid crystal displays (LCDs) and a method of fabricating the same.
2. Description of Related Art
A liquid crystal display (LCD) is one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes and a liquid crystal (LC) layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer, which determines orientations of LC molecules in the LC layer to adjust polarization of incident light.
Typically, one panel has pixel electrodes arranged in a matrix type, while the other panel has a common electrode which covers the whole surface of the other panel. The LCD displays images by applying a separate voltage to each pixel electrode, with each pixel electrode connected to a TFT to control the voltage for each pixel electrode. The TFT is connected to a gate line, which transmits a gate signal, and a data line that transmits a data signal. In general, the TFT is a switching device for controlling a voltage (display) signal supplied to each pixel electrode.
Conventionally, photolithography with masks is used repeatedly to pattern multiple thin film layers and to form the TFT. Different laminated layers having different shapes may be formed by photolithography using one mask, rather than a number of masks, to decrease manufacturing costs. However, when different laminated layers are patterned by photolithography using one mask (e.g., photolithography process using a photoresist pattern as an etching mask), a patterned upper layer can be consumed during patterning of an underlying layer (e.g., width of the thin film is narrowed or etched upon patterning a thin film). A design for broadening the width of the overlying layer may solve this problem, but decreases the size of display area or reduces the aperture of pixels.